Chondroitin lyase (EC 4.2.2.4) or chondroitinase ABC is an enzyme which catalyzes the depolymerization of chondroitin sulfate. Through β-elimination of 1,4 hexosaminidic bonds, chondroitinase ABC degrades chondroitin, chondroitin 4-sulfate (chondroitin A sulfate), dermatan sulfate (chondroitin B sulfate), chondroitin 6-sulfate (chondroitin C sulfate) and hyaluronate to the respective unsaturated disaccharides (Δdi-OS for chondroitin, Δdi-4S for chondroitin A sulfate, Δdi-4-6S for chondroitin B sulfate and Δdi-6S for chondroitin C sulfate, respectively). The enzyme has been isolated in various strains of bacteria (Neuberg, C. et al., (1914) Biochem. Z. 67: 82-89) (Neuberg, C. et al. (1931) Biochem, Z. 234: 345-346; Yamagata, T. et al., (1968) J. Biol. Chem. 243: 1523-1535) including Proteus vulgaris (Yamagata, T. et al. (1968) J. Biol. Chem. 243: 1523-1535; Thurston, C. F. (1974) J. Gen. Microbiol. 80: 515-522; Sato N. et al. (1986) Agric. Biol. Chem. 50: 1057-1059; Sato N. et al. (1986) Biotechnol. Bioeng. 28: 1707-1712; Sato, N. et al. (1986) J. Ferment. Technol. 64: 155-159).
Chondroitin sulfate consists of alternating β 1-3 glucuronidic and β 1-4 N-acetylgalactosaminidic bonds, and is sulfated at either C-4 or C-6 of the N-acetylgalactosamine pyranose. Chondroitin sulfate is known to be widely distributed in mammalian tissue, such as in skin, cornea, bone and especially in cartilage. Thus, chondroitinase ABC has been used as an experimental reagent for the determination or quantitation of total amount of galactosaminoglycans in the field of orthopedic surgery (Linker, A. et al. (1960) J. Biol. Chem. 235: 3061-3065; Saito, H. et al. (1968) J. Biol. Chem. 243: 1536-1542; Pettipher, E. R. et al. (1989) Arthritis Rheum. 32: 601-607; Caterson, B. et al. (1990) J. Cell Science 97: 411-417; and Seibel, M. J. et al. (1992) Arch. Biochem. Biophys. 296: 410-418).
Recently, chondroitinase ABC has been reported to be a potential reagent for chemonucleolysis, an established treatment for intervertebral disc displacement (Kato, F. et al. (1990) Clin. Orthop. 253: 301-308; Henderson, N. et al. (1991) Spine 16: 203-209). However, for the utilization of chondroitinase ABC as a clinical reagent, there are many problems to be overcome. For example, the preparation of chondroitinase ABC from P. vulgaris requires tedious and intricate procedures, since the cellular content of the enzyme is low. Therefore, an efficient method for the efficient preparation of highly purified chondroitinase ABC is now sought.